The present invention relates to a process for the production of a low calorie cellulose food filler with an improved flavour or texture, more particularly a powdered cellulose food filler.
In the preparation of low calorie foods the general method is to reduce the proportion of carbohydrate and fat in the food. However, if the carbohydrate and fat content were reduced without adding a substitute, there would be a reduction of bulk volume and change of texture of the food product. Therefore a bulking agent with a low calorie content is needed to provide the bulk volume and reduce the caloric density of the food. The bulking agents are known as low calorie fillers.
Fat and oil may be replaced by recently developed fillers such as sucrose polyester and polyglycerol esters which have the characteristics of oil and fat but have a much lower calorie content.
Carbohydrate may be replaced by two types of filler, one being a soluble material for replacing sugar and the other being an insoluble material for replacing starch and flour. The most common materials used for replacing starch and flour are dietary fibres or the so-called "unavailable" carbohydrates, examples of which are pectic substances, gums, mucilages, hemicellulose, cellulose and lignins. Of these materials, purified cellulose is most effective because of its high fibre content, good shelf life and negligible levels of microbial contamination. There are two purified celluloses available commercially, these being powdered cellulose and microcrystalline cellulose of which powdered cellulose is the most used in low calorie foods because of its lower cost. However, there are two major disadvantages of powdered cellulose when used in foods. One is that it possesses an undesirable cardboard taste and odour and the second is that it has a very gritty texture after rehydration. Because of the undesirable taste and odour, the palatability of foods containing powdered cellulose has always been a problem and this has meant that only a limited amount of powdered cellulose could be used not only in low calorie foods but also in high fibre foods such as breakfast cereals in which calorie reduction is not necessary but addition of fibre content is beneficial. This undesirable taste and odour is most significant when the powdered cellulose is used in instant foods which require minimum or no cooking.
It is common practice to add flavouring ingredients to powdered cellulose but this only masks or neutralises the cardboard taste and odour of the cellulose. For example, U.S. Pat. No. 4,089,981 describes a process for making simulated foods by adding flavouring agent, gelling agent, oil and water to the cellulose with mild temperature pasteurisation at 165.degree. F., but the flavour of the cellulose itself is not altered.